Traffic congestion is a condition on a road network that occurs as use increases and is characterized by slower speeds, longer trip times, and increased vehicular queueing. Several travel demand management techniques have been attempted to alleviate traffic congestion. For example, HOT lanes (High occupancy/toll lanes) can be employed to encourage people to share rides and thus decrease the amount of vehicles on the roads.
HOT lanes can be implemented in the context of a road pricing scheme that provides motorists in a vehicle access to a HOV (High Occupancy Vehicle) lane. Sometimes entire roads can be designated for the use of HOVs. Tolls can be collected either by a manned toll booth, automatic number plate recognition, or an electronic toll collection system. Typically, these tolls increase as traffic density and congestion within the tolled lanes increases, a policy known as congestion pricing. The goal of this pricing scheme is to minimize traffic congestion within the lanes. The pricing scheme in HOT lanes can be implemented utilizing a static approach and a dynamic approach. The prices can be defined based on time of the day in the static approach. Such an approach, however, cannot maintain a level of service in the HOT lanes (e.g., average speed, throughput, etc.) since it does not dynamically adjust the HOT toll rate in real-time.
With the advent of electronic toll collection systems, pricing can also be accomplished dynamically so that the tolls can be set in real-time depending on the traffic conditions. The majority of prior art dynamic pricing algorithms are elementary in nature and do not consider the dynamics of the system. Although some dynamic pricing algorithms utilize a feedback control law, they often result in fluctuations with respect to average speed or throughput in the HOT lanes. Such fluctuations can arise when there are time delays or traffic jams present in the HOT lanes.
Based on the foregoing, it is believed that a need exists for an improved method and system for providing a feedback based dynamic pricing algorithm with an embedded controller for a high occupancy toll lane, as will be described in greater detail herein.